快速排序C++

#include <iostream>
#include <vector>
using namespace std;



void show(vector<int>& a) {
    for (int i = 0; i <= a.size() - 1; i ++) {
        cout << a[i] << " ";
    }
    cout << endl;
}


int quick_sort(vector<int>& a, int left, int right) {

    if (left > right) {
        return -1;
    }

    int pivot = a[left];

    int i = left;
    int j = right;

    while (i != j) {
        while(i < j && a[j] >= pivot) {
            j--;
        }
        a[i] = a[j];


        while (i < j && a[i] <= pivot) {
            i++;
        }
        a[j] = a[i];

    }

    a[i] = pivot;

    quick_sort(a, left, i - 1);
    quick_sort(a, i + 1, right);


}




int main() {
    vector<int> a;
    int t;

    for(int i = 1; i <= 5; i++) {
        cin >> t;
        a.push_back(t);
    }

    quick_sort(a, 0, a.size() - 1);
    show(a);


}